This project is concerned with investigating the sperm specific proteins which appears during spermatogenesis in the rabbit. Plasma membrane proteins will be prepared from isolated and separated populations of rabbit spermatogenic cells. The membrane proteins obtained from these staged cell populations will be analyzed electrophoretically to determine stage differences. Sperm specific proteins which have been identified will then be isolated using column chromatography or preparative electrophoresis and used to produce immune globulins. The isolated proteins can also be used to determine the presence of antibodies in auto-immune sera specific to these proteins. Finally, utilizing peroxidase conjugate labelling techniques, antibodies produced against specific membrane proteins will be used to study the synthesis, intracellular localization, mobility, and insertion of molecules into the plasma membrane. Characterization of the sperm specific membrane antigens has important implications in the understanding of autoimmunity in vasectomized and infertile men and isoimmunity in immunologic infertility in women. Furthermore, this study should provide valuable information on synthesis and fate of specific membrane proteins.